extend myphpadmin time out

[MacLion]

Hi, I am wondering how I can extend or stop phpmyadmin from timing out?I read somewhere that I need this $cfg['LoginCookieValidity']=60 * 60 * 10; to config.inc.php, this file is completely blank by default, after I added it, it crashes phpmy admin. Then I added the sam,e $cfg['LoginCookieValidity']=60 * 60 * 10; to config.sample.inc.php, it didn't crash, but it also does nothing to change the time out. Is there another config file that phpmyadmin reads? or another way to stop this phpmyadmin annoyance?

Thanks.